Pinning mechanism in a continuous ultrafine Nb3Al multifilamentary superconductor.

For Nb3Al multifilamentary superconductors fabricated by a newly developed composite process using continuous ultrafine Al-based alloy cores and pure Nb matrix, Jc properties have been investigated in detail in regard to the size and morphology of the Al core. A significant enhancement in pinning force caused by reducing the Al core size and an anisotropy in Jc observed in a rolled tape have indicated that the Nb3Al-matrix (or core) interface acts as a dominant pinning center of fluxoids. [ABSTRACT FROM AUTHOR]